Tray/container system for cleaning/sterilization processes

ABSTRACT

A method for cleaning/sterilizing a medical device with a lumen comprises the steps of: a) providing a container having one enclosure and one openable and closeable interface separating the container and the enclosure, b) placing the device on a tray, c) placing the tray into the container and enclosure so that one end of the device and a portion of the tray are located in the container and the other end of the device and another portion of the tray are located in the enclosure, d) creating a pressure difference between the two ends, e) cleaning the device with a cleaning solution, f) rinsing the device with rinse solution, g) treating the device with a chemical germicide. An apparatus for cleaning/sterilizing a device with a lumen comprises a container having at least two separated close compartments. An openable and closeable interface separates the container into the compartments. A tray is adapted to be placed in the two compartments crossing the interface for accommodating the device, so that one end of the device is in one compartment and the other end is in the other compartment. A source for creating a pressure difference is provided. A cleaning mechanism adapted to clean the device is also provided.

BACKGROUND OF THE INVENTION

This invention relates to systems and processes for cleaning, chemicalsterilizing or disinfecting medical devices.

Medical instruments have traditionally been sterilized or disinfectedusing either heat such as is provided by steam, or a chemical in liquid,gas, or vapor state. Prior to sterilization or disinfection, theinstruments to be treated are usually first cleaned and then sterilizedor disinfected. After sterilization or disinfection with a liquidchemical germicide, purified water is used to rinse the instruments andthen the instruments are dried. Numerous publications regarding thecleaning of medical devices and the sterilizing of medical devices areavailable.

U.S. Pat. No. 5,443,801 discloses a transportable cleaning/sterilizingapparatus and method for inside-outside washing and sterilization ofmedical/dental instruments. The apparatus functions in four sequentialcycles: wash, rinse, sterilize, and dry. The sterilization step isconducted using ozonated and purified water, and the drying step isaccomplished by injecting ozonated/deozonated sterile warm dry oxygen,or sterile inert gas into and exhausted from the wash chamber under apositive pressure relative to atmospheric. In this process, the devicehas to be rinsed with purified water after it is sterilized to removesterilant residue before drying step.

U.S. Pat. No. 5,505,218 to Steinhauser et al. discloses a device forcleaning, disinfecting and maintaining medical or dental instruments.The device has a pot-shaped container with a multiplicity of mountingsin the interior of the container each for one of tool holder, a watersupply system, a compressed air supply system, and an ultrasonictransducer. The disinfection is conducted with heated water, and thedrying is conducted with hot compressed air. This system is not designedfor sterilization.

U.S. Pat. No. 5,279,799 to Moser et al. discloses apparatus for cleaningand testing endoscopes by injecting pressurized air into the sheath andpressurized air and washing liquid into the ducts. A washing chamber isprovided which contains retractable cages to hold the endoscopes duringcleaning and testing. This process includes washing, disinfecting, finalrinsing with purified water, and air drying the ducts of a tubulararticle. A number of filters are involved in this system, and thissystem is not designed for sterilization.

U.S. Pat. No. 4,744,951 to Cummings et al. discloses a two-chamberedsystem which provides hydrogen peroxide in vapor form for use insterilization processes. The sterilant is initially vaporized in onechamber and then applied to the object to be sanitized in another singlesterilizing chamber, thereby producing a concentrated hydrogen peroxidevapor which is relatively more effective. The sterilization processesare designed for furnishing concentrated hydrogen peroxide vapor tointerior surfaces of articles having a tortuous or a narrow path.However, the sterilization processes are ineffective at rapidlysterilizing lumened devices, since they depend on the diffusion of thehydrogen peroxide vapor into the lumen to effect sterilization.

U.S. Pat. No. 4,863,688 to Schmidt et al. discloses a sterilizationsystem consisting of a liquid hydrogen peroxide vaporization chamber andan enclosure for sterilization. The enclosure additionally may holdcontainers wherein the hydrogen peroxide sterilant vapor does notcontact the interior of the containers. This system is designed forcontrolling the exposure to the hydrogen peroxide vapor. The system isnot designed for sterilizing a lumen device.

U.S. Pat. No. 4,943,414, entitled "Method for Vapor Sterilization ofArticles Having Lumens," and issued to Jacobs et al., discloses aprocess in which a vessel containing a small amount of a vaporizableliquid sterilant solution is attached to a lumen, and the sterilantvaporizes and flows directly into the lumen of the article as thepressure is reduced during the sterilization cycle. This system has theadvantage that the water and hydrogen peroxide vapor are pulled throughthe lumen by the pressure differential that exists, increasing thesterilization rate for lumens, but it has the disadvantage that thevessel needs to be attached to each lumen to be sterilized.

U.S. Pat. Nos. 4,937,046, 5,118,471 and 5,227,132 to Anderson et al.each disclose a sterilization system which uses ethylene oxide gas forsanitation purposes. The gas is initially in a small first enclosure andthereafter slowly permeates into a second enclosure where the objects tobe sterilized are located. A medium is then introduced into the secondenclosure to flush out the sterilizing gas into a third enclosurecontaining the second enclosure. An exhaust system then exhausts thesterilant gas and air from the third enclosure. These systems also havethe disadvantage of relying on the diffusion of the sterilant vapor toeffect sterilization and hence are not suitable for rapidly sterilizinglumened devices.

U.S. Pat. No. 5,122,344 to Schmoegner discloses a chemical sterilizersystem for sterilizing items by vaporizing a liquid chemical sterilantin a sterilizing chamber. Pre-evacuation of the sterilizer chamberenhances the sterilizing activity. Sterilant is injected into thesterilizer chamber from a second prefilled shot chamber. This systemalso relies upon diffusion of sterilant vapor to effect sterilizationand is also not suitable for rapidly sterilizing lumened devices.

U.S. Pat. No. 5,266,275 to Faddis discloses a sterilization system fordisinfecting instruments. The sterilization system contains a primarysterilization chamber and a secondary safety chamber. The secondarysafety chamber provides for sensing and venting to a destruction chamberany sterilization agent that is released from the primary sterilizationchamber. This system, as in other systems, also relies upon diffusion ofsterilant vapor to effect sterilization and is also not suitable forrapidly sterilizing lumened devices.

In U.S. Pat. Nos. 5,492,672 and 5,556,607 to Childers et al, there isdisclosed a process and apparatus respectively for sterilizing narrowlumens. This process and apparatus uses a multicomponent sterilant vaporand requires successive alternating periods of flow of sterilant vaporand discontinuance of such flow. A complex apparatus is used toaccomplish the method. Additionally, the process and apparatus of '672and '607 require maintaining the pressure in the sterilization chamberat a predetermined subatmospheric pressure.

In U.S. Pat. No. 5,527,508 to Childers et al., a method of enhancing thepenetration of low vapor pressure chemical vapor sterilants into theapertures and openings of complex objects is disclosed. The methodrepeatedly introduces air or an inert gas into the closed sterilizationchamber in an amount effective to raise the pressure to a subatmosphericpressure to drive the diffused sterilant vapor further into the articleto achieve sterilization. The '508, '672 and '607 Childers inventionsare similar in that all three require repeated pulsations of sterilantvapor flow and maintenance of the sterilization chamber pressure at apredetermined subatmospheric pressure.

One disadvantage of the cleaning/sterilizing or cleaning/disinfectingsystems of the prior art as discussed above is that, after the device issterilized or disinfected and before it is dried, the device has to berinsed with purified water to remove disinfectant or sterilant residues.A so-called bacteria filter is usually used to filter the water toremove particulates and bacteria. Typically, a two-stage filteringsystem is utilized, for example, a first stage has a 2-5 micron filterand a second stage has a 0.1-0.2 micron filter. However, virus can besmaller than 0.1 micron. This means the virus can penetrate thefiltering system recontaminating the sterilized device in the finalrinsing process. Another problem associated with the use of a bacteriafilter is that bacteria can form biofilms in the filter which aredifficult to sterilize and, thus, become a new potential source ofcontamination.

In consideration of the foregoing, no simple, safe, effective method ofcleaning, sterilizing or disinfecting, drying devices with an integratedprocess and with the sterilizing (or disinfecting) and drying beingconducted simultaneously exists in the prior art. Thus, there remains aneed for a simple and effective process and apparatus for efficientlycleaning, sterilizing or disinfecting, and drying medical devices,especially those with long narrow lumens.

SUMMARY OF THE INVENTION

One aspect of the present invention provides a cleaning/sterilizing orcleaning/disinfecting process which incorporates cleaning, sterilizing(or disinfecting) and drying of a lumen or non-lumen medical device intoan integrated process, i.e. the device is cleaned, sterilized and driedin situ in the same apparatus in a operation cycle. Especially, thesterilizing and drying are conducted simultaneously. In other words,after the device is sterilized, there is no need to further rinse thesterilized device like the prior art does. Thus, there is no need for afiltering system.

Another aspect of the present invention relates to an apparatus forcleaning, sterilizing, or disinfecting medical devices, especiallydevices with lumens. The apparatus comprises a container with aninterface for separating the container into enclosures. The interfacehas an opening equipped with specially designed holder(s) foreliminating or reducing occlusion area.

Still another aspect of the present invention relates to amulti-compartment container. The container has a specially designed trayfor accommodating a lumen device. The tray is placed across and sealedagainst an interface separating the container into enclosures.

The method of the present invention for cleaning and sterilizing ordisinfecting a medical device with a lumen having at least two open endscomprises the steps of: a) providing a container having at least oneenclosure and at least one openable and closeable interface separatingthe container and the enclosure, b) placing the device on a tray, c)placing the tray into the container and enclosure so that one end of thedevice and a portion of the tray are located in the container and theother end of the device and another portion of the tray are located inthe enclosure, d) creating a pressure difference between the two ends togenerate a flow through the lumen of the device, e) cleaning the devicewith a cleaning solution, f) rinsing the device with a rinse solution,g) treating the device with a chemical germicide. The interface may havetwo plates forming a gap therebetween for passing the tray, and surfacesof the two plates facing the gap are adapted to seal around the tray andthe device on the tray. The method further comprises retaining apredetermined amount of the chemical germicide in the container andenclosure and vaporizing the retained chemical germicide to sterilize ordisinfect and dry the device under vacuum, and providing a dry producton tray without further rinsing. The sterilizing or disinfecting can beconducted under a diffusion restricted environment, or by reducingpressure to a first predetermined pressure followed by further reducingsaid first pressure to a predetermined second pressure, or at controlledpump down rate. In one embodiment, a substantially horizontal surfacehaving wells thereon for retaining a predetermined amount of fluid isprovided in the container or enclosure. The cleaning solution comprisesa detergent solution or an enzyme solution, and the chemical germicidecomprises hydrogen peroxide or peracetic acid. The method furthercomprises removably attaching the container to a vacuum system anddetaching the container after the device is sterilized or disinfectedand dried. The device to be treated can be an endoscope. In addition,non-lumen devices also can be treated together with the lumen device.

The apparatus of the present invention for cleaning/sterilizing orcleaning/disinfecting a device with a lumen having at least two openends comprises a container having at least two separated closecompartments. An openable and closeable interface separates thecontainer into the compartments. A tray is adapted to be placed in thetwo compartments crossing the interface for accommodating the device, sothat one end of the device is in one compartment and the other end is inthe other compartment. A source for creating a pressure differencebetween the two ends of the device to generate a flow through the lumenof the lumen device is provided. A cleaning mechanism adapted to cleanthe device is also provided. In one embodiment, the interface has afirst and a second portion, the first portion includes a seat with afirst edge secured and sealed to an interior periphery of the containerand a second edge configured to contact an exterior periphery of thetray, the second portion of the interface is a plate having an edgeadapted to contact an interior periphery of the tray and an exteriorperiphery of the device placed on the tray. The interior periphery ofthe container lies in a plane substantially perpendicular to alongitudinal axis of the container, the interior and exterior peripheryof the tray also lies substantially in the plane. Preferably, theinterior periphery of the container forms a rectangle with one openside, the interior and exterior periphery of the tray also forms arectangle with one open side. The interior periphery of the containermay form a rectangle with one open side, the interior and exteriorperiphery of the tray also has a bottom edge and two side edgesextending from the bottom edge upwardly and outwardly. The first andsecond edge of the seat and the edge of the plate of the interface canbe equipped with a compressible material, an expandable material, or acompressible material on top of an expandable material. Preferably, thesecond edge of the seat and the edge of the moveable plate of theinterface is further equipped with compressible material on top of theexpandable material. The tray can be notched at the interior andexterior periphery of the tray to restrain movement of the tray alongthe longitudinal axis of the container. The tray may have a bottom walland four side walls substantially perpendicular to the bottom walldefining a first space for receiving the device, the bottom and sidewalls of the tray have holes thereon, the container has a bottom walland four side walls substantially perpendicular to the bottom walldefining a second space for receiving the tray. The container orenclosure may comprise a substantially horizontal surface having wellsthereon capable of retaining a predetermined amount of liquid. Thecleaning mechanism can be selected from the group consisting of astirrer, a liquid jet, an air jet, a turbulent flow, an ultrasonics, anda bubble generator. The interface is removable. The interface can form aseal around said lumen device and the tray selected form the groupconsisting of a gas-tight seal, a tight-fit, and a loose-fit. Theapparatus may further comprise a vacuum system, and wherein thecontainer comprises a gas-permeable and microorganism-impermeablebarrier and is removable attached to the vacuum system. Thegas-permeable and microorganism-impermeable barrier can be equipped witha valve to control the opening and closing of gas communication betweenthe vacuum system and the container through the barrier. The source forgenerating a pressure difference can be a liquid pump or compressed air.The apparatus may further comprise a vacuum pump for applying vacuum andfor serving as the source for generating a pressure difference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a schematic diagram of a container used in acleaning/sterilizing process of the present invention.

FIG. 1b is a schematic diagram of a stirrer with fluid inlets used inthe container of FIG. 1.

FIG. 1c is a schematic diagram of a gas-permeable butmicroorganism-impermeable barrier installed in a vacuum port of thecontainer of FIG. 1.

FIG. 1d is a schematic diagram of a container placed in a vacuum chamberused in a cleaning/sterilizing process of the present invention.

FIG. 1e is a schematic diagram of a container with fluid jet tubes.

FIG. 2 is a schematic diagram of a container with an adaptor used in thecleaning/sterilizing process of the present invention.

FIG. 3a is a schematic diagram of a container with an interface used inthe cleaning/sterilizing process of the present invention.

FIG. 3b is a schematic diagram of a shutter used in the interface of thecontainer of FIG. 3a.

FIG. 3c is a schematic diagram of a iris valve used in the interface ofthe container of FIG. 3a.

FIGS. 3d, 3e, and 3f are schematic diagrams of two plates forming anopening in the interface of the container of FIG. 3a.

FIG. 3g is schematic diagram of an interface of the container of FIG.3a.

FIG. 4 is a schematic diagram of a container placed in a vacuum chamberused in the process of the present invention.

FIG. 5a is a schematic diagram of a container having two holders in aninterface.

FIGS. 5b and 5c are schematic diagrams of two holders of the containershown in FIG. 5a holding a lumen device.

FIG. 5d is a schematic diagram of an interface of a container withmultiple openings.

FIG. 6 is a schematic diagram of a container separated into threeenclosures by two interfaces according to the present invention.

FIG. 7a is a schematic diagram of a container having an interface and atray across the interface according to the present invention.

FIGS. 7b and 7c are cross-sectional views of the container of FIG. 7a atthe location of the interface.

FIG. 8a is a top view of the container of FIG. 7a.

FIG. 8b is a top view of a portion of the interface of FIG. 7a.

FIG. 8c is a top view of the tray of FIG. 7a.

FIG. 8d is a top view of the container of FIG. 7a without the tray andthe interface.

FIG. 9 is a schematic diagram showing a recycle system for processingliquid.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The cleaning/sterilizing or cleaning/disinfecting process of the presentinvention can be carried out with various apparatus and incorporatedwith various sterilization methods, which are described below.

Method to Deliver a Predetermined Amount of Liquid Sterilant

This method can be incorporated into the cleaning/sterilizing orcleaning/disinfecting process of the present invention. In order tomaximize the efficiency of a vapor sterilization process, it isimportant and desirable to drain excess sterilant solution and only keepa desired amount of the sterilant solution to vaporize after treating adevice to be sterilized with the sterilant solution.

According to the present invention, a sterilization container orenclosure may have a surface with wells thereon which define a knownvolume. The well is positioned so that when a liquid sterilant isintroduced onto the surface, a known volume of the liquid sterilantfills the well and when the liquid sterilant is drained from thesurface, the known volume of liquid sterilant remains in the well sothat a subsequent vapor sterilization process can be performed on thedevice with the known volume of liquid sterilant positioned within thesurface. The surface preferably has at least one perforation fordraining the liquid sterilant from the surface. The well formed in thesurface can be curved, flat or angled. Thus, the well can be an inwardlyextending hemispherical projection. The well can also be formed in thesurface as an inwardly extending rectangular projection having roundedends. The well formed in the surface can also be a rectangular boxhaving side walls, defining an opening. Where perforations are provided,they can be disposed adjacent the well, and can be roughly spherical inshape. The upwardly extending projection can include a perforationthereon, which can be on top of the projection or on a side of theprojection. The surface can be a sloped surface, a convex or concavesurface or a V-shaped surface. The surface can be made of a variety ofmaterials including stainless steels, aluminum, aluminum alloys, liquidcrystal polymers, polyesters, polyolefins polymers or fluorinatedpolyolefins. If the surface is comprised of a composite material, thecomposite material can include a filler of high thermal conductivity.Examples of composite materials include a metal-filled polymer, aceramic-filled polymer and a glass-filled polymer. Those materials arealso suitable for the side walls and doors of the sterilizationcontainer.

A tray with wells with configurations similar to that described abovecan be provided with a container or enclosure. The tray can be securedto the container or removably placed in the container.

Method Based on Diffusion Restricted Environments

A method of vapor sterilization or disinfection underdiffusion-restricted environments can also be used in corporation withthe cleaning/sterilizing or cleaning/disinfecting process of the presentinvention. In this method, the devices (lumen or non-lumen) to besterilized are pretreated with a sterilant solution, and then exposed topressures less than the vapor pressure of sterilant. Both the exteriorand interior surface areas of a lumen or non-lumen device can beeffectively sterilized by taking advantage of the diffusion-restrictedenvironments within lumens or within a container or enclosure.

As used herein, a "diffusion-restricted" area refers to any one or moreof the following properties: (1) the ability of the area of an articleplaced within the sterilization system of the present invention toretain 0.17 mg/L or more hydrogen peroxide after one hour at 40° C. and10 torr; (2) having the same or more diffusion restriction than providedby a single entry/exit port of 9 mm or less in internal diameter and 1cm or greater in length; (3) having the same or more diffusionrestriction than provided by a lumen 27 cm in length and having aninternal diameter of 3 mm; (4) having the same or more diffusionrestriction than provided by a lumen having a ratio of length tointernal diameter greater than 50; (5) the ability of an article placedwithin the sterilization system of the present invention to retain 17%or more of the starting 1 mg/L hydrogen peroxide solution initiallyplaced therein after one hour at 40° C. and 10 torr; or (6) beingsufficiently diffusion-restricted to completely sterilize a stainlesssteel blade within a 2.2 cm by 60 cm glass tube having a rubber stopperwith a 1 mm by 50 cm stainless steel exit tube therein at a vacuum of 10torr for one hour at 40° C. in accordance with the present invention. Itis acknowledged that characteristics (1) and (5) will vary depending onthe initial concentration of hydrogen peroxide placed into the article;however, this can be readily determined by one having ordinary skill inthe art.

This method includes the steps of contacting the exterior and interiorof a device with a sterilant solution, and then exposing the device to anegative pressure or vacuum for a period of time sufficient to effectcomplete sterilization. For example, when 1 mg/L of hydrogen peroxide isused as sterilant, if the exposing step is conducted for 1 hour at 40°C. and 10 torr, the diffusion restricted area preferably retains 0.17mg/L or more hydrogen peroxide, or retains 17% or more of the hydrogenperoxide placed therein after the exposing step. In certain preferredembodiments, the diffusion-restricted area has the same or morediffusion restriction than provided by a lumen 27 cm in length and aninternal diameter of 3 mm, or has the same or more diffusion restrictionthan provided by a lumen having a ratio of length to internal diametergreater than 50. The contacting step can be performed by either a director an indirect contact procedure. Direct contacting includes methodssuch as injection, static soak, flow-through, condensation of a vapor,or aerosol spray, or mist spray. Any other methods involving physicallycontacting the devices to be sterilized with a sterilant would beconsidered direct contacting. Indirect contacting includes those methodsin which sterilant is introduced into the chamber or container, but notdirectly on or on the devices to be sterilized. The exposing step ispreferably performed for 60 minutes or less, and is preferably performedat a pressure less than the vapor pressure of the sterilant. Thus, thepreferred pressure range under conditions of the present invention isbetween 0 and 100 torr. The exposing step can include the step ofheating the device, such as by heating the container in which theexposing step occurs. The container can be heated to about 40° C. toabout 55° C. Alternatively, the sterilant solution can be heated, suchas to a temperature of about 40° C. to about 55° C. Optionally, the stepof exposing the device to a plasma can be conducted during the step ofexposing the device to negative pressure or vacuum. In one embodimentemploying exposure to plasma, the method is performed within a firstchamber and the plasma is generated in a second separate chamber. Thisembodiment further comprises the step of flowing the plasma into thefirst chamber. Advantageously, the contacting and/or exposing steps ofthe method can be repeated one or more times.

Method Based on Controlled Pump-Down Rate

The cleaning/sterilizing process of the present invention can also becarried out in cooperation with a controlled pump down method withoutrelying on a diffusion-restricted environment.

Effective sterilization results similar to those created indiffusion-restricted environments can be created through controlling theevacuation rate of a chamber or container in which devices to besterilized are placed. Thus, in one embodiment of the present invention,this controlled pump-down rate method comprises the steps of contactingthe device with a liquid sterilant at a first pressure; draining excessliquid sterilant to retain a predetermined amount of the sterilant, anddecreasing the pressure of the chamber to a second pressure below thevapor pressure of the liquid sterilant in which at least a portion ofthe decrease in pressure below about the vapor pressure of the liquidsterilant occurs at a pump down rate of less than 0.8 liters per second,calculated based on the time required to evacuate the chamber fromatmospheric pressure to 20 torr when the chamber is empty and dry, i.e.when the chamber has neither devices to be sterilized nor a visiblequantity of liquid within it. According to one aspect of this preferredembodiment, at least the decrease in pressure below about two times thevapor pressure of the liquid sterilant occurs at a pump down rate ofless than 0.8 liters per second. According to another embodiment, thedecrease in pressure below about four times the vapor pressure of theliquid sterilant occurs at a pump down rate of less than 0.8 liters persecond. Preferably, the pump down rate is 0.6 liters per second or less;more preferably, 0.4 liters per second or less; and most preferably, 0.2liters per second or less. Advantageously, the first pressure isatmospheric pressure. Preferably, the liquid sterilant is hydrogenperoxide. The hydrogen peroxide usually is a solution as used in theart, preferably it is a 3-60% solution. The device can be a lumen ornon-lumen medical instrument.

The present invention can also incorporate a method for sterilizing adevice comprising the steps of (a) contacting the device with liquidsterilant at a first pressure; (b) retaining a predetermined amount ofthe liquid sterilant in the container; (c) pumping down the container orchamber to a second pressure which is lower than the first pressure at afirst rate; and (d) pumping down the container or chamber to a thirdpressure which is lower than the second pressure, wherein at least aportion of the pumping down to the third pressure is at a second ratewhich is slower than the first rate. The pump down rate either aboveand/or below the second pressure can be constant or variable. In certainembodiments, the pump down rate either above and/or below the secondpressure is reduced in stepwise fashion. Preferably, the second pressureis greater than or equal to about the vapor pressure of the liquidsterilant; more preferably, the second pressure is greater than or equalto about two times the vapor pressure of the liquid sterilant; mostpreferably, the second pressure is greater than or equal to about fourtimes the vapor pressure of the liquid sterilant. Advantageously, thepump down rate in step (d) is 0.8 liters/sec or less; moreadvantageously 0.6 liters/sec or less; even more advantageously 0.4liters/sec or less; and most advantageously 0.2 liters/sec or less,calculated based on the time required to evacuate the chamber fromatmospheric pressure to 20 torr under empty and dry conditions.Preferably, the liquid sterilant is hydrogen peroxide. In anotherembodiment, the device is a medical instrument having a lumen.Preferably, the pumping down of step (c) reduces the pressure to lessthan about three times, more preferably to less than about two times,the vapor pressure of the liquid sterilant.

Another suitable method includes contacting the device with liquidsterilant, retaining a predetermined amount of the liquid sterilant inthe container, and reducing the pressure of the chamber while regulatingthe pump down rate so as to control the evaporation rate of sterilant insaid chamber. In any of the methods described above, the contacting stepmay comprise application of liquid or condensed vapor. These methodsdescribed above may additionally comprise further evacuating the chamberto remove residual sterilant. Further, these methods described above mayadditionally comprise exposing the device to plasma to remove residualsterilant or enhance sterilization efficacy. The contacting step inthese methods can be either by direct or indirect contacting. As statedherein, indirect contacting involves introducing sterilant into thechamber without directly contacting the device to be sterilized.

Two Step Pump-Down Method

A two step pump down sterilization method can also be used incooperation with the cleaning/sterilizing process of the presentinvention. This method comprises the steps of contacting a device withliquid sterilant; draining excess liquid sterilant to retain apredetermined amount of the sterilant; bringing the pressure of thechamber to a first pressure range at which the liquid sterilant isvaporized from non-diffusion restricted area of the device to sterilizethe non-diffusion restricted area; bringing the pressure of the chamberto a second pressure range at which the liquid sterilant is vaporizedfrom diffusion restricted area of the device to sterilize the diffusionrestricted area, wherein the minimum pressure in the second pressurerange is lower than the maximum pressure in the first pressure range.

Preferably, the first pressure range is from 20 to 760 torr; morepreferably, the first pressure range is 20 to 80 torr; most preferably,the first pressure range is 40-50 torr. Advantageously, the secondpressure range is 1-30 torr; more advantageously, the second pressurerange is 5-10 torr. In one preferred embodiment, the device includes adiffusion-restricted environment. Preferably, the device is a medicalinstrument with a lumen. Advantageously, the sterilant is hydrogenperoxide. According to another aspect of this preferred embodiment, thechamber is at a set temperature and wherein the first pressure ispreferably lower than the vapor pressure of the sterilant at the settemperature. Preferably, the pressure of the chamber is maintainedconstant at the first pressure for a time period sufficient to sterilizethe non-diffusion restricted area. Advantageously, the pressure of thechamber is maintained constant at the second pressure for a time periodsufficient to sterilize the diffusion restricted area. The pressure ofthe chamber may be permitted to increase after reaching the first orsecond pressure range as a result of vaporization of the sterilantwithin said chamber. Alternatively, the pressure of the chamber ispermitted to decrease after reaching the first or second pressurethrough pumping of said chamber at a rate slower than used to decreasethe pressure between said first and second pressure ranges. Preferably,the contacting step is with liquid, condensed vapor, or mist. The methodcan also include the steps of bringing the pressure to a third pressurelower than the second pressure to remove residual sterilant and/orexposing the device to plasma to remove residual sterilant or enhancesterilization efficacy.

Method Involving Direct Flow Through a Lumen of the Device to BeSterilized

A method of directly flowing fluid through a lumen of a medical deviceto be treated can be incorporated with the cleaning/sterilizing orcleaning/disinfecting process of the present invention. An apparatus canbe used to efficiently clean and sterilize devices with long narrowlumens by flowing a fluid such as a cleaning solution or a sterilant,either in liquid phase or in vapor phase, directly through the lumens oflumen devices to be sterilized.

The flow of a germicide (solution or vapor), or any cleaning solutionthrough a lumen of a medical device is driven by a pressure drop betweentwo open ends of the lumen. The pressure drop can be generated byapplying either a vacuum or a high pressure at one end. By generating aforced flow through a pressure differential other than relying ondiffusion, the sterilization rate is significantly increased and lesstime is needed for a sterilization cycle.

It is clear that the two ends of the lumen need to be exposed to apressure differential. This is achieved in the present invention byplacing a sealable interface between two chambers, two enclosures, or acontainer and an enclosure to separate them from each other. Preferably,an opening is provided in the interface and the lumen device to besterilized is placed through the opening so that the lumen serves as aflow path between the two chambers or between the container and theenclosure.

The opening can be constructed in several ways. One way to achieve thisis with a camera shutter approach employing an iris diaphragm, such as aprecision iris diaphragm from Edmund Scientific. An optional spring canbe used to secure the closure of the shutter. Also commerciallyavailable is Syntron Iris Flow Control Valve manufactured by FMCCorporation. This Iris Valve has a sleeve made of Teflon or othersynthetic material defining an aperture. By rotating two ends of thesleeve relative to each other, the aperture can be reduced or increased.Iris diaphragm valves from Kemutec Inc. are also commercially availablewhich can be automatically controlled. Another example is the AirGripperand AirPicker manufactured by Firesone Industrial Products Company.Another way to construct an openable and closeable opening is to employtwo plates. Two edges of the two plates form a gap which can be adjustedby moving the two plates relative to each other. One or more lumendevices are placed through the gap formed between the two plates and thetwo plates are moved together to form a seal around the lumen devices.The edges of the two plates forming the gap can be equipped withcompressible material or expandable material. When expandable materialis used, a fluid source can be provided to expand the expandablematerial. Optionally, a porous material like a sponge or air permeablematerial may be utilized on the edges. In this case some sterilant candiffuse through the porous material to the outer surface of the lumendevice occluded by the closed opening. However, most the sterilant flowsthrough the lumen device. Another usable interface is a hole or a slot,the hole or slot is equipped with gas or liquid inflatable material sothat by inflating the inflatable material on the hole or the slot theopening is reduced and the lumen device is held and sealed. Stillanother option is to place a compressible material on top of anexpandable or inflatable material so as to facilitate the sealing aroundthe lumen device.

The closing and opening movement of the opening can be controlledmechanically or electronically with any conventional mechanism. Thedegree of opening is adjustable. Thus, it can be sealed to a differentdegree between the opening and the lumen device depending on the desiredpurpose. For example, the opening can form a gas-tight seal, atight-fitting seal, or a loose-fitting seal around the lumen device. Asused herein, a gas-tight seal refers to a seal that substantially stopsliquid and gas flow through the contact area between the opening and thelumen device surface. When a gas-tight seal is employed, preferably thedevice to be sterilized is first pre-cleaned so that the occluded areaby the seal is cleaned before the gas-tight seal is formed. Aloose-fitting seal allows both liquid and gas to flow through the gapbetween the opening and the lumen device surface, and in the meantime isable to maintain a pressure drop across the interface enough to generatea flow through the lumen. A tight-fitting seal allows gas and liquid topenetrate to the contact area between the opening and the lumen devicesurface by diffusion. For example, a tight-fitting seal can be formedwith porous material or textures provided on the contact surface of theopening. Thus, for gas-tight seal the device is held tightly by theclosed opening. In the tight-fitting seal, the closed opening also holdsthe device in position. In the case of a loose-fitting seal, the devicecan move relative to the opening, but is not flashed away.

The interface can be made openable, closeable, and removable, and mayhave more than one opening. In order to promote sterilizationefficiency, all the sterilization apparatus of the present invention canbe further equipped with a heater and/or a plasma.

Specially Designed Containers

As used herein, the terms "container" and "enclosure" are exchangeable.The present invention provides a container specially designed toeliminate or minimize occlusion area which usually corresponds to thecontact area between a lumen device surface and a closed opening of aninterface holding the device. The occlusion area is hard to reach byeither liquid or vapor because of the close contact between twosurfaces. Thus, the cleaning and sterilizing of an occlusion area isadversely affected by such contact. Several approaches have been takenin the present invention to deal with this occlusion problem.

One approach is to reduce the contact area by using porous material,textures, sharp projections, or sharp edges on the contact surface ofthe opening of the interface, or an adaptor or a connector. In this way,cleaning and sterilizing fluid can either flow or diffuse to most partof the contact surface of the device which is held by the closed openingfairly tightly and, in the meantime, the contact area between theopening and the device surface will impose a resistance to fluid flowhigh enough to allow a pressure difference to exist between two sides ofthe interface. Thus, a flow through the lumen of the device can begenerated and maintained if desired. Another advantage of this approachis that the contract area generated through the above means can becontrolled to provide a diffusion restricted environment at the contactarea, which will increase the efficiency of the sterilization process.

Another approach is to use multiple holders in the opening. For example,two holders can be secured to the opening along its passage. Preferably,each of the holders is independently controllable and sealable. During acleaning or sterilizing process, the two holders are alternately openedand closed, i.e. one is open while the other is close. In this way, agood seal between the two sides of the interface can be maintained andthe device can be held tightly during a sterilization process.Meanwhile, the contact areas on the device surface caused by the twoholders are exposed to cleaning or sterilizing fluid alternately.

Still another approach is the combination of the above two approaches.In this approach, the contact surface of the interface, or the opening,or the holder has multiple contact points. The contact points can beprojections, teeth, blades, sharp edges, or any other suitable form andshape. These contact points can be controlled separately so that aportion of the contact points is made in contact with the device to besterilized while the others are not. By alternately changing theposition of the contact points, all the occlusion areas will be exposedto the sterilant. An example of such a multiple contact point structureis a shutter with multiple blades. Those blades can be separatelycontrolled for opening and closing.

The present invention also provides a container with a speciallydesigned tray. It is often desirable to place the device to besterilized on a tray so that after the device is cleaned and sterilized,it can be transported on the tray without being touched. This reducesthe chance of contamination through touching the device. In theapparatus of the present invention, a tray is placed across an openableand closeable interface between a container and an enclosure or betweentwo compartments or enclosures, a lumen device is placed on the trayalso across the interface. When the interface is in a closed condition,a seal is formed between the opening of the interface and the tray andthe lumen device.

Various apparatus of the present invention which can be used to carryout the cleaning/sterilizing or cleaning/disinfecting process of thepresent invention is described in more detail by reference to thedrawings. In the following figures like numbers refer to like partsthroughout.

FIG. 1a shows a container 2 used in a cleaning/sterilizing process ofthe present invention. Container 2 has a sloped bottom wall 4 leading toa fluid source 7. A fluid port 6 is provided at the lowest point ofsloped bottom wall 4. Apparently, sloped bottom wall 4 can be configureddifferently and the lowest point can be located Cin any location withinthe sloped bottom wall 4. For example, instead located in the positionas shown in FIG. 1a, the lowest point, thus the fluid port 6, can belocated at one end or a corner of the sloped bottom wall 4. A valve 8 isprovided at fluid port 6 to control fluid flow in and out container 2.Below sloped bottom wall 4 is a flat lower bottom 14. The lower surfaceof the sloped bottom wall 4 is equipped with a number of transducer 16for providing ultrasonic cleaning. A number of wells 18 are provided ona plate 17 located above the upper surface of the sloped bottom wall 4and below rotating arm 22. Plate 17 can be of any appropriate shape andmade rotatable, so that unwanted liquid retained in wells 18 can beremoved by rotating plate 17. Well 18 can have different shapes and iscapable of retaining a predetermined amount of sterilant as describedearlier. Plate 17 can be removably placed on the upper surface of thesloped bottom wall 4 or secured to the upper surface in a horizontalorientation. One or more stirrer 20 is installed either on sloped bottomwall 4 or on an upper wall 24 or on both. Rotating arm 22 of the stirrer20 can be made hollow or contains channels connecting to an outsidefluid source through the body of the stirrer 20. As shown in FIG. 1b,stirrer 20 can be connected to a water source 21a, an air source 21b,and a drain 21c, each of them is controlled by a valve. Water jet or airjet 26 can be provided through the channels of rotating arm 22.Container 2 can also be made of jacket walls with holes thereon so thatthe water or air jet can be provided through those holes opened on thejacket walls. Container 2 also has a lower grid 28a and an upper grid28b. Preferably, grid 28b and 28a has a flat shape and horizontallyplaced inside container 2 at an upper and a lower position,respectively. A space defined by lower grid 28a, upper grid 28b and sidewalls of container 2 is used to accommodate a device to be treated. Atray 30 can be placed in the space and the device is placed in the tray30 for cleaning and sterilizing. Stirrer 20 is located either in thespace defined by upper wall 24, upper grid 28b and side walls ofcontainer 2, or in the space defined by sloped bottom wall 4, lower grid28a and side walls of container 2, or in both. Container 2 furthercontains a vacuum port 32 located at the upper portion of container 2.Preferably, vacuum port 32 is located on the upper wall 24 of container2 to avoid liquid in container 2 from entering vacuum port 32. Agas-permeable but microorganism-impermeable barrier 34 is secured to thevacuum port 32. Any conventional method can be used to seal barrier 34into vacuum port 32 such as shown in FIG. 1c. In the connection shown inFIG. 1c, barrier 34 is placed in a barrier holder 34a. The barrierholder 34a is placed into a seat 34b formed between two end of twotubes. An O-ring 34c is provided around holder 34a. Thus, by clampingthe two ends of the two tubes toward each other barrier 34 is securedand sealed. A valve 36 is provided at vacuum port 32. A vacuum pump 38is connected to vacuum port 32 through valve 36. A detachable connectorcan be provided between valve 36 and vacuum pump 38.

Container 2 of FIG. 1a can be placed into a vacuum chamber with slightmodification. As shown in FIG. 1d, the same container 2 is used exceptthat barrier 34 provided on upper wall 24 is not connected directly tothe vacuum port 32 which is provided on the wall of a vacuum chamber 66.

FIG. 1e shows another way of providing a fluid jet in container 2.Instead of stirrers, several tubes 22a with small holes thereon aresecured vertically in container 2 to provide a fluid jet such as a waterjet or an air jet. Tube 22a can be positioned to provide an uniformspray, the orientation and shape of tube 22a can be determined accordingspecific purposes. The rest parts can be the same as the container ofFIG. 1a.

When using the above described container in the cleaning/sterilizingprocess of the present invention, one first places a device into thecontainer 2. The device can be either placed on the lower grid 28a orplaced in tray 30. Two grids 28a and 28b set the boundaries for thedevices in the container and keep the device from being damaged bystirrer 20. The upper grid 28b is the fluid fill line to ensure all thedevices are immersed in the fluid. Usually the device is firstpre-cleaned in container 2 by a water jet to remove majority of soils,large particles, and other contaminates. During the pre-cleaning, thedrain is usually kept open to remove the dirty water containing thoseparticles and contaminates. Then the device is cleaned. In this step acleaning solution is filled into container 2 through a liquid pump. Thecleaning solution can be any conventional cleaning solution with enzymeand detergent solution preferred. During the cleaning step, stirrers,water jet, ultrasonics, or other suitable mechanism can be used tofacilitate the cleaning process. When the cleaning is complete, thecleaning solution is drained through fluid port 6. A rinse solution isthen introduced into container 2 through fluid port 6. The rinsesolution can be water, alcohols, or other rinse liquid. The rinsing canbe facilitated by stirrers, water jet, air bubbles, or other suitablemechanism. These steps can be repeated if desirable. After the rinsingstep, air can be introduced through stirrer 20 to blow water off thedevice. Then a liquid sterilant is introduced into container 2 from thesame fluid port, and the device is treated with the liquid sterilant fora desired time. Preferably, the liquid sterilant is a hydrogen peroxidesolution or a peracetic acid solution. The main purpose of this step isto treat the device with the liquid sterilant and to provide rightamount of the liquid sterilant. The sterilization is achieved mainly innext step. If necessary, excess of the liquid sterilant can be drainedfrom container 2, and a predetermined amount of the liquid sterilantwill be retained by the wells 18. This amount of liquid sterilant isdetermined based on the size of the load, the container, and the vacuumchamber. At this point, vacuum pump 38 is turned on and vacuum isapplied to container 2 through vacuum port 32. In this step, thediffusion restricted environment method, the controlled pump down ratemethod, the two step pump down method discussed previously can beemployed to achieve good sterilization results. When the sterilizationis finished, container 2 is detached from the vacuum system, the devicecan be kept in container 2 and stored for future use. The sterility ofthe sterilized device is maintained in container 2 because container 2is sealed except for the gas-permeable but microorganism-impermeablebarrier 34. In one embodiment, valve 36 is closed when the pressure incontainer 2 is lower than atmospheric pressure and container 2 includingthe sterilized device is stored for use. This procedure provides afurther means to check if the sterility of the device is well maintainedin the container. If the container 2 is still under a pressure below theatmosphere before next use of the device, that means no air leaking intocontainer 2 and, thus, no microorganism can enter container 2 during thestorage. Any one of the above steps can be repeated if desirable. Thesterilizing step can also be replaced with a disinfecting step by usinga proper germicide.

FIG. 2 shows a container having adapters for connecting lumen devices.Similar to the container of FIG. 1a, container 2 shown in FIG. 2 has asloped bottom wall 4 with a first fluid port 6 at the lowest point ofthe sloped bottom wall 4. Several stirrers are installed on the slopedbottom wall 4. A flat sheet metal grid 28a is horizontally located atthe lower portion of container 2. Grid 28a, sloped bottom wall 4, andside walls of container 2 define a space accommodating stirrer 20 andwells 18 on plate 17. An adapter 40 is connected to a second fluid port42 at one end and the other end for receiving a lumen device 46. Agas-tight seal, tight-fitting, or loose-fitting between adapter 40 andlumen device 46 can be formed. Adapter 40 can be any suitableconventional adapters used in the art. Preferably, the second fluid port42 is located above grid 28a. Second fluid port 42 is also connected toa source 44 for generating a pressure difference between the two ends ofa lumen device 46 which is connected with the second fluid port 42through adapter 40. Source 44 can be a liquid pump for generatingnegative pressure, or a positive pressure. Lumen device 46 is placed ontop of the grid 28a. Like the container shown in FIG. 1a, container 2 ofFIG. 2 also has a vacuum port 32 with a gas-permeable butmicroorganism-impermeable barrier 34 and a valve 36. The barrier coversthe vacuum port 32 and blocks passage for microorganism, valve 36controls the opening and closing of the vacuum port 32. As shown, fluidport 6 and stirrers 20 are also connected with a tube 9 for drainingfluid from container 2 or supplying fluid jet to stirrer 20. One end oftube 9 leads to a waste fluid collector, the other end is connected topump 44.

FIG. 3a shows a container 2 separated into a first enclosure 50a and asecond enclosure 50b by an interface 52. As shown both enclosure 50a and50b have a sloped bottom wall 4 with stirrer 20 secured thereon, a flatsheet grid 28a horizontally positioned at lower portion of enclosure 50aand 50b, and a fluid port 6, respectively. A pump 54 is provided betweenthe two fluid ports 6. A vacuum port 32 is provided at the upper portionof enclosure 50a and 50b. A gas-permeable but microorganism-impermeablebarrier 34 is connected to the vacuum port 32 to stop microorganism fromentering enclosure 50a and 50b through vacuum port 32. Vacuum port 32 isalso equipped with a valve 36 and a source 44 for generating pressuredifference and providing vacuum. Preferably, source 44 is a vacuum pumpfor providing negative pressure or compressed air for providing positivepressure. Interface 52 has a controllable opening 56 (also referred asholder). Lumen device 46 is placed across opening 56 partly in enclosure50a and partly in enclosure 50b. Opening 56 can be configureddifferently. For example, opening 56 can be made of a shutter 58 such asan iris diaphragm as shown in FIG. 3b, and the opening and closing ofopening 56 can be controlled manually or automatically. In oneembodiment, the blades of shutter 58 (eight blades are shown in FIG.3b), can be divided into two groups. For example, each group containsfour blades not next to each other. These two groups of blades arecontrolled separately by a controller so that while one group is in theclose position holding the device to be sterilized the other group is inopen position allowing the sterilant to sterilize the area occluded bythe blades when the blades are in closed position. Another example ofshutter 58 is the Syntron Iris Flow Control Valve (by FMC Corporation)or the Iris diaphragm valves (Kemutec Inc.) as shown in FIG. 3c.Briefly, Iris valve 58a has a cylindrical sleeve 90 with two retainingrings 92 located at two ends of the cylindrical sleeve 90. Sleeve 90 ismade of Teflon or other suitable plastic or rubber material. When inuse, a lumen device is inserted through an aperture 94 of cylindricalsleeve 90. A first retaining ring 92 is secured and sealed to opening56, a second retaining ring 92 is free to rotate and coupled tointerface 52 through a conventional mechanical mechanism (not shown) sothat the turning of the second retaining ring 92 can be controlledmechanically or electronically from outside container 2. By rotating theretaining rings 92 relative to each other, the diameter of aperture 94of the cylindrical sleeve 90 can be increased or reduced, or totallyshut off. If desirable, more than one shutter can be provided in theinterface 52.

Opening 56 also can be a slot or a gap defined by two plates 59 as shownin FIGS. 3d and 3e. The contact edges or surfaces of plate 59, whichform the slot and hold the lumen device 46, are equipped with a layer ofexpandable material 60 such as silicon, or a layer of compressiblematerial 62. The closing, and thus seal around lumen device 46, of theslot can be done either by moving plate 59 or expanding expandablematerial 60. With a two-plate opening 56, more than one lumen device canbe placed across the opening 56. When expandable or inflatable materialis used on plate 59, an expansion fluid source can be provided to plate59 to expand the expandable material 60. In one embodiment, a layer ofcompressible material 62 is provided on top of the layer of expandablematerial 60 as shown in FIG. 3f. In another embodiment, the opening 56is formed by an upper plate 59a and a lower plate 59b as shown in FIG.3g. The lower plate 59b has a rectangular shape with a bottom edge andtwo side edges being secured and sealed to the bottom wall and two sidewalls of container 2, respectively. The upper plate 59a also has arectangular shape and its upper portion is movably inserted into ahousing 53a. Housing 53a forms the upper portion of interface 52. Aportion of housing 53a extends along two side walls of container 2 tothe upper edge (or contact surface) of lower plate 59b, forming tworails 53b for receiving the two side edges of upper plate 59a andguiding the movement of the upper plate 59a. There provided a sealbetween the upper plate 59a and the housing 53a and rail 53b. Forexample, an O-ring can be used in housing 53a and rail 53b to seal theupper plate 59a. The upper edge of the lower plate 59b and the loweredge of the upper plate 59a are provided with a layer of compressible orexpandable material. The movement of the upper plate 59a can becontrolled by any suitable conventional method, mechanically orelectrically, form the outside of container 2. Many differentconfigurations and structures can be adopted for the opening 56. Forexample, the contact surface of opening 56 can be made of an unevensurface so that, when opening 56 is closed around a lumen device, theuneven surface will provide passage to allow both liquid and gas to passtherethrough while holding the lumen device. Thus, the occlusion area onthe lumen device surface can be significantly reduced. The unevensurface may have textures, projections, sharp edges, or sharp pointsthereon.

In another embodiment, opening 56 is an aperture equipped with a layerof porous material or with a layer of expandable material and a layer ofporous material on top of the expandable material. Opening 56 also canbe made of an aperture of suitable shape, such as cylindrical, linedwith porous material. A shutter is secured to the aperture providing asteady holding of the lumen device 46 with minimal contact area orocclusion area.

FIG. 4 shows a container 2 with an enclose 50 separated by an interface52. In this embodiment, the container 2 with the enclosure 50 is placedinside and coupled to vacuum chamber 66. Vacuum chamber 66 has a firstvacuum port 68 which is in gas communication with container 2 through agas-permeable but microorganism-impermeable membrane 34 installed on theupper wall of container 2, and which is preferably located at the upperportion of a side wall of vacuum chamber 66. A valve 35 is providedabove membrane 34 to control the opening and closing of gascommunication of container 2 with outside through membrane 34. Vacuumchamber 66 also has a second vacuum port 70 connecting to a vacuum port32 of the enclosure 50 through a valve 36. Preferably, the second vacuumport 70 also located at the upper portion of the side wall of the vacuumchamber and near the first vacuum port 68. Valve 36 is preferablylocated outside the enclosure 50 and inside the vacuum chamber 66. Adetachable connector (not shown) is preferably provided between valve 36and second vacuum port 70 for attaching valve 36 to and detaching valve36 from the second vacuum port 70. The first and second vacuum ports 68and 70 are connected to each other outside the vacuum chamber 66. Avalve 72 is provided at first vacuum port 68 to control flow through thefirst vacuum port 68. A valve 74 can also be provided at the commoninlet of the first and second vacuum ports 68 and 70. A source 44 forgenerating pressure difference between the two ends of the lumen device46 is provided at the common inlet of first and second vacuum ports 68and 70. Preferably, source 44 is a vacuum pump for generating a negativepressure or compressed air for generating a positive pressure. Vacuumchamber 66 also has a first fluid port 76 connecting to a fluid port 6aof the container 2 through a valve 8a, and a second fluid port 78connecting to a fluid port 6b of the enclosure 50 through a valve 8b.The first and second fluid ports 76 and 78 are located at the lowerportion of a side wall of the vacuum chamber 66 and close to each other.The fluid port 6a is located at the lowest point of a sloped bottom wall4a of the container 2. In this embodiment, the fluid port 6a is locatedat one lower corner of the container 2. The fluid port 6b is located atthe lowest point of a sloped bottom wall 4b of the enclosure 50. In thisembodiment, the fluid port 6b is located at one lower corner of theenclosure 50. A detachable connector can be provided for connectingvalve 8a and 8b to first and second fluid port 76 and 78, respectively.Outside the vacuum chamber 66, first and second fluid ports 76 and 78are connected to each other forming a common fluid inlet which isprovided with a valve 80. A liquid pump 54 is also provided between thefirst and second fluid ports 76 and 78 to circulate a fluid between thecontainer 2 and the enclosure 50. The container 2 has a lower grid 28aand an upper grid 28b. Preferably, the lower grid 28a and the upper grid28b are a flat metal sheet and horizontally positioned at the lower andthe upper portion of the container 2, respectively. Stirrers 20 arelocated below the lower grid 28a. Interface 52 has an opening (orholder) 56 for holding a lumen device 46. The opening 56 can beconfigured in many different ways such as those described with FIGS.3b-3f. On the bottom wall of vacuum chamber 66, a plurality oftransducer 16 is provided to generate ultrasonics. Accordingly, thespace between outer surface of the bottom of container 2 and the innersurface of the bottom wall of vacuum chamber 66 is filled with water orother suitable liquids providing a medium for the ultrasonics.

In using the apparatus with containers and enclosures separated by aninterface in the cleaning/sterilizing or cleaning/disinfecting processof the present invention, a lumen device is placed into the container 2and the enclosure 50 across the interface 52. The opening 56 of theinterface 52 is then closed manually or automatically. Thus, opening 56forms a seal around the lumen device. The extent of the sealing can becontrolled through different degree of tightening of the opening 56around the lumen device 46 for different purposes. As definedpreviously, three types of seal can be made between the opening 56 andthe lumen device 46, gas-tight seal, loose-fitting seal andtight-fitting seal. If maximum pressure is intended a gas-tight sealshould be used in this case the container 2 is substantially totallysealed from the enclosure 50, neither gas nor liquid can flow throughthe space between the opening 56 and the lumen device 46. Under manysituations such a gas-tight seal is not necessary. In this case, atight-fitting seal can be used so that a portion of fluid in the systemcan flow or diffuse through the space between the opening 56 and thelumen device 46, but a large portion of the fluid flows through thelumen of the lumen device 46, and the lumen device 46 is still held inposition by the opening 56 during agitation. Loose-fitting will providea opportunity to clean/sterilize the outer surface area of the lumendevice 46 which is otherwise obscured by the opening 56.

A cleaning solution is then introduced into the container 2 and theenclosure 50 through fluid port 6a and 6b, respectively. The liquidlevel in the container 2 and the enclosure 50 is preferably not higherthan the position of the vacuum port 32. A stirrer, a water jet or anair jet can be used to facilitate the cleaning of the outer surface ofthe lumen device 46. The cleaning solution is also circulated betweencontainer 2 and enclosure 50 through the lumen of the lumen device 46.There are at least two ways to make the circulation. One method is toapply vacuum to the enclosure 50 through second vacuum port 70 of vacuumchamber 66 and vacuum port 32 of the enclosure 50 while keeping vacuumchamber 66 and container 2 at atmospheric pressure or any pressurehigher than that of the enclosure 50. This can be done similarly whenvacuum chamber 66 is not used. The cleaning fluid then flows from thecontainer 2 into the enclosure 50 through the lumen device 46. Theliquid pump 54 circulates the cleaning fluid back to the container 2.The opening 56 and the stirrer 20 can be controlled by the electronicsignals from the system. Air bubbles generated from air pump 10 can beintroduced at this stage to enhance the scrubbing action duringcleaning. Thus, both the outer surface and the inner surface of thelumen device 46 can be cleaned at the same time. Vacuum can be appliedto container 2 to generate a pressure in the container 2 lower than thatof the enclosure 50. Forced air also can be used to push liquid throughthe lumen. If desired, the interior and the exterior of the lumen devicecan be cleaned separately. The cleaning fluid can be removed from thecontainer 2 and enclosure 50 through the fluid port 6a and 6b on thesloped bottom wall 4a and 4b. The cleaning fluid in the lumen device 46can be removed either with vacuum or forced-air.

The rinsing with water and the treatment with liquid sterilant can beconducted similarly. When the treatment with a liquid sterilant iscomplete, the liquid sterilant is drained and a predetermined amount ofthe liquid sterilant can be retained in the wells. Then vacuum isapplied to chamber 66 and container 2 either through vacuum port 68 or70, or both in a manner described earlier. At least in certain stage,the vacuum should be high enough (or the pressure low enough) tovaporize the remaining sterilant in container 2 to sterilize and dry thedevice simultaneously. A plasma can be used as an option to enhance theefficacy and/or to remove the sterilant residual. After thesterilization is completed, the chamber is vented and the container isready to be retrieved from the chamber. If desired, valve 35 can beclosed at any pressure below the atmospheric pressure and the sterilizeddevice is kept in container 2 under a subatmospheric pressure. This mayserve as an indication of a well maintained sterility, i.e. if thevacuum still exists when container is opened after a period of time ofstorage that indicates the sterility of the sterilized device is wellkept. The pressure can be monitored and controlled by the pressuresensor on the vacuum chamber 66 or in container 2.

FIG. 5a shows a container very similar to that shown in FIG. 3a exceptthat two holders 100 are used in opening 56 of interface 52. As shown inFIGS. 5a and 5b, the two holders 100 are secured to opening 56 alonglumen device 46 or the passage of opening 56. Each holder 100 is sealedto opening 56 in any suitable conventional manner and each holder 100 isindependently controllable. Holder 100 can be a shutter as the shutterdescribed with FIGS. 3b and 3c, or made of two plates as described withFIGS. 3d-3g. FIG. 5b shows two holders 100 of shutter type holding alumen device 46. During cleaning or sterilizing operation, a firstholder 100 is first closed and a second holder 100 is opened, then thefirst holder is opened and the second holder 100 is closed. Thus,enclosures 50a and 50b are always separated or insulated from each otherthrough the engagement of one holder 100 with the device 46 and, in themeantime, the two contact surface areas of the device 46 occluded by thetwo holders 100 are exposed alternately.

FIG. 5c shows two holders 100 of plate type holding a lumen device 46.Each of holders 100 can be constructed in the way as describedpreviously with FIGS. 3d-3g. Preferably, the gap (the opening forpassing the lumen device) formed between the two plates of one holder100 forms an angle with that of the other holder 100 of the two holderstructure. Preferably, the angle is 90 degree as shown in FIG. 5c. Thetwo holders 100 are preferably positioned close enough so that when theexpandable material 60 lined in the gap (opening) is expanded, theexpandable material 60 will also expand outwardly away from the twoplates and become in contact with the other holder 100, thus help sealthe gap of the other holder 100. This configuration provides anadvantage that no complete seal is needed for a single holder, yet agood seal such as a gas-tight seal can be achieved when two such holdersare combined. It has been noted by the applicants that, when acylindrical lumen device is placed across the gap between the two platesof holder 100, areas on the outer surface of the lumen device, where thediameter of the cylindrical lumen device is parallel to the gap, aremore difficult to seal because the expandable material 60 has to expandextra distance to cover those areas. By providing two closely positionedholders 100 with the two gaps forming an angle, the above mentionedareas in each of the two holders can be sealed by the other holder.Therefore, the requirement to the expandable material can be loweredwithout sacrificing the sealing characteristics.

FIG. 5d shows another embodiment of an interface of the presentinvention. In this embodiment, the interface 52 contains multipleopenings 56c. This interface 52 may have three parts. A first plate 59chas a plurality of openings 56c thereon. The cross section of theopening 56c as viewed from a direction perpendicular to the surface ofplate 59c has an elongate shape with its longitudinal axis extendingalong a substantially vertical direction. Other orientation also can beadopted. Preferably, opening 56c has a rectangular cross section. Theupper side of the openings 56c can be made open for easy access to alumen device. The contact surface of opening 56c is provided with alayer of expandable material 60. A second plate 59d is positioned besidethe first plate 59c in parallel. Plate 59d can be secured and sealed tothe bottom and side walls of container 2 with its upper edge or surfaceequipped with a layer of expandable material 60. A third plate 59e islocated above and aligned with second plate 59d. The third plate can bemade a part of the lid for container 2. The lower edge of plate 59e andthe upper edge of plate 59d form a gap for passing a lumen device. Theedges of the third plate is also provided with a layer of expandable orother sealing material 60. Preferably, the second plate 59d and thethird plate 59e lie in one vertical plane, and the first plate 59c liesin another vertical plane parallel to that containing second plate 59dand third plate 59e. Preferably, the gap formed between plate 59d and59e forms an angle with openings 56c, more preferably the angle is aright angle. In one preferred embodiment, the gap between second plate59d and third plate 59e has a horizontal orientation, and the openings56c have a vertical orientation. The distance between the first plate59c and the second and third plate 59d and 59e can be adjusted dependingon intended purpose. Preferably, they are closely positioned relative toeach other so that when the expandable material 60 on one plate isexpanded, it will become in contact with the other plate to furtherfacilitate seal around the lumen device passing both the gap betweenplate 59d and 59e and the opening 56c of plate 59c. Preferably, thedimension and the expandable material layer of opening 56c is determinedto allow the opening 56c to be closed and sealed when the expandablematerial is expanded even no lumen device is placed through the opening.

FIG. 6 shows a container 2 has three enclosures 50a, 50b, and 50cseparated by two interfaces 52a and 52b, respectively. Enclosure 50b islocated in between and shares interfaces 52a and 52b with enclosure 50aand 50c. Other parts of the container 2 of FIG. 6 are similar to thoseof the container shown in FIG. 3a, and they are indicated by samenumerical references. Two openings 56a and 56b are located in interface52a and 52b, respectively. Two holders 100 are also located in interface52a and 52b. Opening 56a and 56b can be of any form as discussedpreviously. In practice of the process of the present invention, a lumendevice 46 is placed across both opening 56a and opening 56b with one endlocated in enclosure 50a and the other end in enclosure 50c. Theadvantage of the configuration is to help obtain a large pressure dropbetween the two ends of the device 46. Under certain circumstances, theseal between the opening and the lumen device may be not gas-tight, thusit is difficult to keep a large pressure drop at the two sides of theinterface with such a seal. By adding one intermediate enclosure 50b,the pressure drop across each interface 52a and 52b can be kept at arelative low level, yet the total pressure between the two ends of thedevice 46 or, in other words, between enclosure 50a and enclosure 50ccan be still large enough to generate desired flow rate through thelumen of the lumen device 46. If desired, one interface 52a or 52b canbe removed or opened, and in those cases the container 2 can be operatedjust like that of FIG. 3a.

FIG. 7a shows a container 2 separated into an enclosure 50a and anenclosure 50b by an interface 52 similar to the container of FIG. 3aexcept that a tray 110 is placed across interface 52 and located in bothenclosure 50a and enclosure 50b. The tray 110 shown in FIG. 7a has arectangular shape with four side walls perpendicular to a bottom walldefining a space for receiving a lumen device 46. The side and bottomwalls have open holes thereon. As shown in FIG. 7b, interface 52 can beconfigured to have two parts. The first part forms a tray seat 112extending along an interior periphery of container 2. Tray seat 112 hasa first edge secured and sealed to the interior periphery of container 2and a second edge 114 shaped to receive tray 110. Edge 114 has a bottomportion and two side portions defining an open rectangular crosssection. On top of edge 114 is a sealing layer 116 made of expandable,compressible, or other suitable material. When tray 110 is placed intocontainer 2, an exterior periphery of tray 110 will seat on edge 114 andlayer 116. The second part of interface 52 can be a removable plate 118having an edge 120 shaped to fit the shape of an interior periphery oftray 110. On top of edge 120 is a sealing layer 122 made of expandable,compressible, or other suitable material. Plate 118 is inserted intotray 110 along an interior periphery of tray 110. A guide rail can beprovided with tray 110 to guide plate 118 moving along an predeterminedinterior periphery. Different shapes can be used for edge 114 of seat112 and edge 120 of plate 118, as long as the shape matches that of theexterior and interior periphery of tray 110. For example, in oneembodiment, the open rectangular formed by edge 114 and edge 120 shownin FIG. 7b is modified by making the upper edge longer than the bottomedge of the open rectangular and tray 110 has a corresponding shape.This configuration makes it easier to the plate 118 down into tray 110and seal it. Plate 118 can further include an opening 56 of any kind asdiscussed previously with FIGS. 3b-3g. Opening 56 can be located inplate 118 or on edge 120 facing the bottom of tray 110 where lumendevice is placed. In one embodiment, a layer of expandable,compressible, or other suitable sealing material is also provided withtray 110 along the interior periphery where plate 118 is inserted. FIG.7c shows another embodiment in which tray 110 has a partition 111therein. Partition 111 can be made as part of the tray 110. Upper edge111a of partition 111 has a layer of expandable, compressible, or othersuitable sealing material. Partition 111 is aligned with plate 118 sothat when plate 118 is inserted into tray 110 seal can achieved betweenupper edge 111a of partition 111 and lower edge of plate 118, and alumen device can be placed through the gap or opening 56 formed betweenupper edge 111a of partition 111 and lower edge of plate 118. In oneembodiment, in the contact area between tray 110 and interface 52 (orplate 112 and 118), a portion of side and bottom walls of tray 110 isremoved so that in those portion the sealing layer 116 of tray seat 112and the sealing layer 122 of plate 118 of the interface 52 are in directcontact. Plate 118 can be secured to a lid or cover 119 for container 2and, a portion of the lower surface of the cover 119 is provided with alayer of expandable, compressible, or other suitable sealing material toseal the upper edge of the tray 110 and the container 2 as shown in FIG.7c.

When exposed to a pressure difference between enclosure 50a and 50b,tray 110 may be forced to move from high pressure side to low pressureside. In order to prevent this from happening, a stopper mechanism isprovided. In one embodiment as shown in FIGS. 8a-8d which are top viewsof container 2 and tray 110, tray 110 has a rectangular bottom wall 130with two side walls 132 along two longer edges of bottom wall 130 andtwo side walls 134 along two shorter edges of bottom wall 130. There isan indentation on each side wall 132 extending along the entire heightof side wall 132 and substantially perpendicular to bottom wall 130.Container 2 also has a rectangular bottom wall 140 with two side walls142 along the two longer edges of bottom wall 140 and two side walls 141along two shorter edges of bottom wall 140. There is a projection 144 oneach side wall 142 extending along the entire height of side wall 142and perpendicular to bottom wall 140. The surface of projection 144 iscovered with a layer of expandable, compressible, or other suitablesealing material 146. The projection 144 has a shape matching that ofthe indentation 136. When tray 110 is placed into container 2,indentation 136 will engage with projection 146 so as to hold tray 110in position. A tray seat 112 with a layer of sealing material on itsupper surface is provided on bottom wall 140 of container 2 extendingbetween two projections 146. Tray 110 also has two edges 137 on eachside wall 132 extending inwardly from indentation 136. A removable plate118 with a layer of sealing material on its contact edge is insertedinto tray 110 through a rail defined by extruding edge 137. In anotherembodiment, each side wall 141 is provided with a stopper, such as anextrusion, to confine the movement of tray 110 along a directionperpendicular to interface 52.

FIG. 9 shows a recycling system which can be incorporated into anycontainer systems used in the present invention. In this system, usedliquid in a cleaning/sterilizing process is drained or pumped to areservoir 150 through a filter 152. A pump 154 can be provided betweenreservoir 150 and fluid port 6 to help drain the used liquid intoreservoir 150. The filtered liquid in reservoir 150 can be then cycledback to container 2 through a fluid port 6a. If necessary, filter 152can be cleaned by back flash. Reservoir 150 is also equipped withseveral inlets 156 for water, cleaning chemical, and sterilant,respectively, and a drain 158.

The present invention has been described above. Many modifications andvariation of the cleaning/sterilizing or cleaning/disinfecting processand the apparatus in such process may be made without departingsubstantially from the spirit and scope of the present invention.Accordingly, it should be clearly understood that the form of theinvention described and illustrated herein is exemplary only, and is notintended as a limitation on the scope.

What is claimed is:
 1. A method for cleaning and sterilizing ordisinfecting a medical device with a lumen having at least two open endscomprising the steps of:a) providing a container having at least oneenclosure and at least one openable and closeable interface separatingsaid container and said enclosure; b) placing said device on a tray; c)placing said tray into said container and said enclosure so that one endof said device and a portion of said tray are located in said containerand the other end of said device and another portion of said tray arelocated in said enclosure; d) creating a pressure difference between thetwo ends to generate a flow through the lumen of said device; e)cleaning said device with a cleaning solution; f) rinsing said devicewith a rinse solution; g) treating said device with a chemicalgermicide.
 2. A method of claim 1, wherein the interface has two platesforming a gap therebetween for passing the tray, and surfaces of the twoplates facing the gap are adapted to seal around the tray and the deviceon the tray.
 3. A method of claim 1, wherein the method furthercomprises retaining a predetermined amount of said chemical germicide insaid container and said enclosure and vaporizing the retained chemicalgermicide to sterilize or disinfect and dry said device under vacuum,and providing a dry product on said tray without further rinsing.
 4. Amethod of claim 3, wherein the sterilizing or disinfecting is conductedunder a diffusion restricted environment.
 5. A method of claim 3,wherein the sterilizing or disinfecting is conducted by reducingpressure to a first predetermined pressure followed by further reducingsaid first pressure to a predetermined second pressure.
 6. A method ofclaim 3, wherein the sterilizing or disinfecting is conducted atcontrolled pump down rate.
 7. A method of claim 3, wherein asubstantially horizontal surface having wells thereon for retaining apredetermined amount of fluid is provided in the container or enclosure.8. A method of claim 1, wherein said cleaning solution comprises adetergent solution or an enzyme solution, and said chemical germicidecomprises hydrogen peroxide or peracetic acid.
 9. A method of claim 1,further comprising removably attaching said container to a vacuum systemand detaching the container after the device is sterilized ordisinfected and dried.
 10. A method of claim 1, wherein said device isan endoscope.
 11. A method of claim 1, further comprising treating anon-lumen device together with said lumen device.
 12. An apparatus forcleaning/sterilizing or cleaning/disinfecting a device with a lumenhaving at least two open ends comprising:a container having at least twoseparated compartments; an openable and closeable interface separatingsaid container into said compartments; a tray adapted to be placed inthe two compartments crossing said interface for accommodating saiddevice, so that one end of the device is in one compartment and theother end is in the other compartment; a source for creating a pressuredifference between the two ends of the device to generate a flow throughthe lumen of said lumen device; a cleaning mechanism adapted to cleanthe device.
 13. An apparatus of claim 12, wherein said interface has afirst and a second portion, the first portion includes a seat with afirst edge secured and sealed to an interior periphery of the containerand a second edge configured to contact an exterior periphery of thetray, the second portion of the interface is a plate having an edgeadapted to contact an interior periphery of the tray and an exteriorperiphery of the device placed on the tray.
 14. An apparatus of claim13, wherein said interior periphery of the container lies in a planesubstantially perpendicular to a longitudinal axis of the container,said interior and exterior periphery of the tray also lies substantiallyin said plane.
 15. An apparatus of claim 14, wherein said interiorperiphery of the container forms a rectangle with one open side, saidinterior and exterior periphery of the tray also forms a rectangle withone open side.
 16. An apparatus of claim 14, wherein said interiorperiphery of the container forms a rectangle with one open side, saidinterior and exterior periphery of the tray also has a bottom edge andtwo side edges extending from the bottom edge upwardly and outwardly.17. An apparatus of claim 13, wherein said first and second edge of theseat and said edge of the plate of the interface are equipped with acompressible material, an expandable material, or a compressiblematerial on top of an expandable material.
 18. An apparatus of claim 14,wherein said tray is notched at said interior and exterior periphery ofthe tray to restrain movement of the tray along the longitudinal axis ofthe container.
 19. An apparatus of claim 14, wherein said tray has abottom wall and four side walls substantially perpendicular to thebottom wall defining a first space for receiving the device, said bottomand side walls of the tray have holes thereon, said container has abottom wall and four side walls substantially perpendicular to thebottom wall defining a second space for receiving said tray.
 20. Anapparatus of claim 12, wherein said container or enclosure comprises asubstantially horizontal surface having wells thereon capable ofretaining a predetermined amount of liquid.
 21. An apparatus of claim12, wherein said cleaning mechanism is selected from the groupconsisting of a stirrer, a liquid jet, an air jet, a turbulent flow, anultrasonics, and a bubble generator.
 22. An apparatus of claim 12,wherein said interface is removable.
 23. An apparatus of claim 12,wherein said interface forms a seal around said lumen device and saidtray selected form the group consisting of a gas-tight seal, atight-fit, and a loose-fit.
 24. An apparatus of claim 12, wherein saidapparatus further comprises a vacuum system, and wherein said containercomprises a gas-permeable and microorganism-impermeable barrier and isremovable attached to said vacuum system.
 25. An apparatus of claim 24,wherein said gas-permeable and microorganism-impermeable barrier isequipped with a valve to control the opening and closing of gascommunication between the vacuum system and the container through thebarrier.
 26. An apparatus of claim 12, wherein said source forgenerating a pressure difference is a liquid pump.
 27. An apparatus ofclaim 12, further comprising a vacuum pump for applying vacuum and forserving as said source for generating a pressure difference.
 28. Anapparatus of claim 12, wherein said source for generating a pressuredifference is compressed air.